lazy-effect.md

lazyEffect

Suggests avoiding exported zero-argument functions and service members that lazily return Effect or Stream values

Property	Value
Category	Anti-pattern
Default severity	suggestion
Fixable	No
Effect versions	v4
Diagnostic codes	TS377091
Language Service name	lazyEffect
Oxlint name	effecttsgo/lazy-effect

Preview

import { Effect } from "effect"

export interface PreviewService {
  preview: () => Effect.Effect<void>
/**
  ^^^^^^^ effecttsgo(lazy-effect): Interface 'PreviewService' member 'preview' returns a lazy Effect. Effect is already lazy, so wrapping it in a zero-argument function adds unnecessary indirection.
*/
}

Language Service Configuration

See the Language Service setup guide for installation instructions.

{
  "$schema": "./node_modules/@effect/tsgo/schema.json",
  "compilerOptions": {
    "plugins": [
      {
        "name": "@effect/language-service",
        "diagnosticSeverity": {
          "lazyEffect": "warning"
        }
      }
    ]
  }
}

Oxlint Configuration

See the Oxlint setup guide for installation and patching instructions.

{
  "$schema": "./node_modules/@effect/tsgo/oxlint-schema.json",
  "options": {
    "typeAware": true
  },
  "plugins": ["effecttsgo"],
  "rules": {
    "effecttsgo/lazy-effect": "warn"
  }
}